Setup building with glog library

Summary:
To use the library in code, do the following.

  * Include glog, `include "glog/logging.h"`
  * Initialize logging from a main entry point,
    `google::InitGoogleLogging(argv[0]);`
  * Log anywhere from your code, `LOG(INFO) << "Hello world from glog";`

For advanced use, refer to glog's documentation.

Reviewers: mislav.bradac, florijan, dgleich, buda

Reviewed By: mislav.bradac, buda

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D492

CMakeLists.txt

@@ -284,6 +284,7 @@ include_directories(SYSTEM ${CMAKE_SOURCE_DIR}/libs)
 # needed to include configured files (plan_compiler_flags.hpp)
 set(generated_headers_dir ${CMAKE_BINARY_DIR}/generated_headers)
 include_directories(${generated_headers_dir})
+include_directories(SYSTEM ${CMAKE_SOURCE_DIR}/libs/glog/include)
 # -----------------------------------------------------------------------------
 
 # openCypher parser -----------------------------------------------------------
@@ -373,7 +374,8 @@ set(memgraph_src_files
 # -----------------------------------------------------------------------------
 
 # memgraph_lib and memgraph_pic depend on these libraries
-set(MEMGRAPH_ALL_LIBS gflags stdc++fs Threads::Threads fmt antlr_opencypher_parser_lib dl)
+set(MEMGRAPH_ALL_LIBS gflags stdc++fs Threads::Threads fmt
+    antlr_opencypher_parser_lib dl ${CMAKE_SOURCE_DIR}/libs/glog/lib/libglog.a)
 if (READLINE_FOUND)
     list(APPEND MEMGRAPH_ALL_LIBS ${READLINE_LIBRARY})
 endif()
@@ -381,7 +383,8 @@ endif()
 # STATIC library used by memgraph executables
 add_library(memgraph_lib STATIC ${memgraph_src_files})
 target_link_libraries(memgraph_lib ${MEMGRAPH_ALL_LIBS})
-add_dependencies(memgraph_lib generate_opencypher_parser)
+add_dependencies(memgraph_lib generate_opencypher_parser
+                              glog)
 
 # STATIC PIC library used by query engine
 add_library(memgraph_pic STATIC ${memgraph_src_files})

libs/CMakeLists.txt

@@ -21,6 +21,17 @@ set(GFLAGS_BUILD_gflags_nothreads_LIB OFF)
 set(GFLAGS_BUILD_gflags_LIB ON)
 add_subdirectory(gflags)
 
+# Setup google logging after gflags (so that glog can use it).
+# We need to use `ExternalProject`, because currently glog's CMakeLists.txt
+# doesn't detect gflags if we do `add_subdirectory`.
+include(ExternalProject)
+ExternalProject_Add(glog DEPENDS gflags
+  PREFIX ${CMAKE_SOURCE_DIR}/libs/glog
+  SOURCE_DIR ${CMAKE_SOURCE_DIR}/libs/glog
+  CMAKE_ARGS -DCMAKE_BUILD_TYPE=Release
+             -DCMAKE_INSTALL_PREFIX=${CMAKE_SOURCE_DIR}/libs/glog
+             -Dgflags_DIR=${CMAKE_CURRENT_BINARY_DIR}/gflags)
+
 # setup cppitertools
 # CLion compatiblity; the target won't be built
 file(GLOB __CPPITERTOOLS_SOURCES __main.cpp

libs/setup.sh

@@ -47,6 +47,13 @@ cd googletest
 git checkout ${googletest_tag}
 cd ..
 
+# google logging
+git clone https://github.com/google/glog.git
+glog_tag="a6a166db069520dbbd653c97c2e5b12e08a8bb26" # v0.3.5
+cd glog
+git checkout ${glog_tag}
+cd ..
+
 # lcov-to-coberatura-xml
 git clone https://github.com/eriwen/lcov-to-cobertura-xml.git
 lcov_to_xml_tag="59584761cb5da4687693faec05bf3e2b74e9dde9" # Dec 6, 2016